1. Field of the Invention
The present invention relates to a printing apparatus which conveys sheets using a conveying roller, and performs printing.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2009-6655 discloses a printing apparatus which directly measures speed at a sheet surface with a speed sensor, and controls ink discharge timing of a print head. FIG. 10 is a diagram illustrating in a simplified manner the printing apparatus disclosed in FIG. 25 of Japanese Patent Laid-Open No. 2009-6655. A sheet 500, wound in the form of a roll, is conveyed by an upstream side conveying roller pair 501 and a downstream side conveying roller pair 502, and printing is performed thereupon by a print head 503. A speed sensor 504 (laser Doppler sensor) for directly measuring the moving speed of the sheet is positioned between the upstream side conveying roller pair 501 and the print head 503. The driving control timing of the print head 503 is corrected in accordance with the conveying speed measured at the speed sensor 504, thereby realizing high-quality printing.